These #10 Brass Bolts come with a nut and washer each and are available 1/2" or 3/4" or 1" long. Used as a replacement for the nut/bolt that comes with many new traps in order to get the play out of the pan. Simply drill the pan post and pan shank with a #14 drill bit, and replace the factory nut/bolt with this #10 brass nut/bolt/washer.